Re: Carnoy's fixative II

From:"J. A. Kiernan"

"Atoska S. Gentry" wrote:
> Hello, does anyone have a recipe for Carnoy's fixative II?  If so will you
> please share it with me?  I have only been able to find Carnoy's fixative.

According to JR Baker's "Principles of Biological Microtechnique"
(p.141) JB Carnoy introduced 2 fixatives: 
  (a) In 1886 a 3:1 alcohol-acetic mixture, which is now
usually called Clarke's fluid because JL Clarke had already
published it in 1851.
  (b) In 1887 the 60:30:10 alcohol-chloroform-acetic mixture
that is now what's meant by Carnoy's fixative. As the later
introduction, this one might be "Carnoy II" but I've not seen
that term before now.

If you got the term "Carnoy II" from a modern source, 
it may well mean a more recent modification of the 
alcohol-chloroform-acetic formula. There are at least two
that are quite often used: Methacarn (Puchtler et al 1970)
has methyl alcohol instead of ethyl, and is said to be superior
for muscle and collagen. The "modified Carnoy" of James & 
Tas (1984) is 60:30:5 ethanol-chloroform-acetic; the lower 
concentration of acetic acid gives better preservation 
of RNA. 

This doesn't tell you what "Carnoy II" is, but perhaps it
will help you choose the best fixative for your purposes!

Refs: Methacarn - Puchtler H et 4 al. Histochemie 21:97 (1970).
      Modified Carnoy - James J & Tas J Histochemical Protein 
      Staining Methods. RMS Handbk #4. Oxford:OUP, p.12 (1984).
John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London,   Canada   N6A 5C1

<< Previous Message | Next Message >>